<!DOCTYPE HTML>
<html>
<head>
    <title>My WebSocket</title>
    <script src="https://apps.bdimg.com/libs/jquery/2.1.4/jquery.min.js"></script>
</head>

<!--<body>-->
<!--<input id="text" type="text" />-->
<!--<button onclick="send()">Send</button>-->
<!--<button onclick="closeWebSocket()">Close</button>-->
<!--<div id="message"></div>-->
<!--</body>-->

<body>
<!--显示消息-->
<!--<textarea id = "debuggerInfo" style="width: 100%; height: 200px;"></textarea>-->
<div>user: <input type="text" id = "userId"></div>
<!--发送消息-->
<div>msg: <input type="text" id = "msg"></div>
<button onclick="send()">Send</button>
<button onclick="closeWebSocket()">Close</button>
<div id="message"></div>
</body>

<script type="text/javascript">
    var userId = -1;
    var websocket = null;
    var host = window.location.host;
    userId = GetQueryString("userId");
    //判断当前浏览器是否支持WebSocket, 主要此处要更换为自己的地址
    wsUri = "ws://" + host + "/websocket/" + userId;
    if ('WebSocket' in window) {
        websocket = new WebSocket(wsUri);
    } else {
        alert('Not support websocket')
    }

    //连接发生错误的回调方法
    websocket.onerror = function() {
        setMessageInnerHTML("error");
    };

    //连接成功建立的回调方法
    websocket.onopen = function(event) {
        //setMessageInnerHTML("open");
    }

    //接收到消息的回调方法
    websocket.onmessage = function(event) {
        setMessageInnerHTML(event.data);
    }

    //连接关闭的回调方法
    websocket.onclose = function() {
        setMessageInnerHTML("close");
    }

    //监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。
    window.onbeforeunload = function() {
        websocket.close();
    }

    //将消息显示在网页上
    function setMessageInnerHTML(innerHTML) {
        document.getElementById('message').innerHTML += innerHTML + '<br/>';
    }

    //关闭连接
    function closeWebSocket() {
        websocket.close();
    }

    //发送消息
    function send() {
        // var message = document.getElementById('text').value;
        // websocket.send(message);


        //将输入框中的数据封装成json发送到后端
        var toUserId = $("#userId").val();
        var msg = $("#msg").val();
        var data = {"fromUserId": userId,"toUserId": toUserId,"msg": msg}
        websocket.send(JSON.stringify(data));
    }

    function GetQueryString(name) {
        var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
        var r = window.location.search.substr(1).match(reg);
        var context = "";
        if (r != null) {
            context = r[2];
            reg = null;
            r = null;
            return context = null || context == "" || context == "undefined" ? "" : context;
        }
    }

</script>
</html>